This post is shared: Anyone who spent late nights playing video in a friend’s dorm will recall the joys of setting-up a local-area networking (LAN) back in the days before Wi Fi was available. Although it was a great way to have fun with friends while playing video games, the benefits of setting up multiple LANs on one router offer a number of important benefits for IT professionals and businesses.
Given the difficulties of configuring and maintaining a single network on a router’s router, network administrators (or those managing networks at home) tend to avoid configuring multiple LANs from a single router.

Before we get into the details of configuring multiple networks on one router, let’s discuss why it can be useful.
There are many reasons to set up multiple LANs.
It’s possible for businesses to pay to purchase and maintain separate networks, but small businesses can do this with one wireless router if the device supports it. Many wireless router vendors offer wizard-based configurations for small businesses and the home. This is usually limited to two LANs, one for your private network and one as a guest network for everyone else.
A large company may need to provide Wi-Fi for all employees. However, it will also need to separate the data of the finance department from the marketing data. This will require an understanding of how the network hardware creates and delivers traffic. This configuration would not be done on a wireless router, but on a multi-layer switch or dedicated router.
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What are the basics? This is the foundation of how the Internet and all connected devices interact with one another. It gives unique numerical identifiers for everyone and everything on the Internet. Every router, modem, switch, modem and other networking hardware within a private network or office has an assigned IP address. A single IP address is divided into two sections: Network ID or Host ID. The Network ID is the logical group in which devices belong. The remaining section (HostID) is the unique device within this grouping. To apply multiple networks, it is necessary to understand the location of the network division in order to create smaller networks.
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Once we have a better understanding of how traffic flows through networks we can then dive into the main methods to set up multiple LANs from one router: subnets or virtual local area networks (VLANs).
SubnetsSubnets are logical groups of addresses we use to separate networks. Subnetwork can be done on a single network. Subnetting is a method that takes a single network, and divides it into smaller networks. Why would you do it? Let’s suppose you have an existing network address block assigned. Subnetting can be used to re-allocate it to make it more useful by creating smaller networks called “subnets”.

Let’s take, for example, a typical corporate office. One address block–1 network was assigned to you with a limited number of hosts. There are Finance, Marketing, HR, and other departments that have different bandwidth and security requirements. The router is a networking machine that controls traffic and sends packets to and from an external network. Each department will have its own interface – marketing, finance, and HR will each have their own subnet. These interfaces will be equipped with an IP address that will serve as the default gateway address for each subnet. The router will then route traffic between subnets and to the Internet.
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Although subnetting networks are a powerful way for enterprise IT teams to manage and regulate security needs in each department they serve it is not always the best fit. Virtual local area networks serve similar functions, using hardware resources to segment a network instead of setting IP masks.
Virtual Local Area Networks, or VLANs, are physical switches that are logically equivalent to one LAN. VLANs allow us to take one physical switch and group ports into multiple smaller switches. Each smaller group would be a VLAN. This configuration is not the only one. Multiple switches can be connected to a single VLAN to allow ports to be grouped together and work as one switch.
VLANs are used to secure at-home users. They block traffic and offer strong security.